Propeller



W.,V.KA|\/IP AND T. Rl MACMECHEN.

PROPELLER.

APPLICATION FILED IAN. 13, 1920.

' tmy Patented Mar., 29, IisIzII.

Thomas @Maa/Weeber.

WI T NESS INV ENTORZ UNHTED STATES WALTER V. KAMP AND THOMAS R. BEACMECHEN, 0F PHLADELPHA, PENNSYLVANIA.

PROPELLER.

Specification of Letters Patent.

rateiiteu Mar. ae, resi.

Application ined January 13, 1920. serial No. 351,0a5.

To all whom t may concern.'

Be it known that we,'\VALTER V. KAMP and 'THoafrAs R. MACMECHEN, citizens of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented new and useful improvements in Propellers, of which the following is a specification.

This invention relates to propellers and it has more particular reference to blades therefor, the main object being to provide a structure or form of blade which practically eliminates all slippage no matter at what speed the propeller is run. Furthermore any increase or decrease in the velocity of a propeller the blades whereof are fashioned in accordance with my present invention will not involve a pro rata increasel or decrease in the consumption of the particular power employed for rotating said propeller.

Another object of this invention is to provide a propeller blade which will give the maximum propulsive effect no matter in which direction it is rotated; that is to say whether it is employed for a drive ahead or astern.

lVith the foregoing primary objects in view our invention consists essentially in forming the propeller blade of suitable material and having a medial portion the edges whereof are parallel and the opposed ends converging therefrom in hyperbolic curves to the tips.

In the further disclosure of the invention reference is to be had to the accompanying sheet of explanatory drawings constituting a part of this specification and in which like characters of reference designate the same or similar parts in all the views.

Figure 1 is a fragmentary side view of a propeller showing one of our improved blades applied thereto.

Fig. 2 is a detail plan view of the blank from which a blade is fashioned.

Fig. 3 is an end view of the structure shown in Fig. 1.

Fig. 4 is an end view of the blade by itself, looking at the same from a slightly different angle than the angle in which it is shown in t:Fig 3.

Fig. 5 is an enlarged transverse section through the blade.

Referring to the views the numeral 10 designates part of a tail or propeller shaft on which are suitably mounted spaced opposed hubs 11, from which project or to which are attached opposed arms 12, that support the blade designated generally for the purpose of this description by the numeral 13. It will be seen by reference to Fig. 1 that the arms 12 projecting from the hubs 11 connect with the blade 13 near its ends, and although the mounting may be brought about in any desired manner, it will be clearly apparent that the mounting shown provides for the positioning` of the blade 13 in offset relation to the shaft; that is to say, the blade is not mounted centrally of the shaft or hubs, but to one side. Obviously any other convenient or appropriate means: may bc employed for mounting the blades 13 relative to their supporting hub or boss, and we lay no claim whatever in this specification to the means for mounting said blades.

Now referring more specifically to Figs. Q to 5 inclusive which illustrate one practical embodiment of our invention we take a blank of sheet steel 14-Fig. 2-the longitudinal sides 15 whereof are parallel and from the opposed points 16 we shear or cut-away in reverse directions the end portions so that oppositely disposed hyperbolic curved edges 17, result which sweep from the points 16, to the tips 18, of the blade 13. This blank or blade 13 is then bent or otherwise suitably shaped to have a concavo-convex transverse cross-section as shown to an enlarged scale in Fig. 5, and the tips 18 are twisted into a line directly central of the length of said blade, as shown in Fig. 3, and the blade may now be tempered or braced to withstand the torsional strains set up when in use.

While we have shown and described a type of blade which is suitable for use on ventilating fans, airship propellers and for analogous uses; it will be obvious that heavier types of blades may be forged or cast on identical lines for use on ships propellers and under heavier service conditions, and we wish it clearly understood that we do not limit ourselves in any way to the specific embodiment hereinbefore particularly referred to but consider ourselves at liberty to make such changes as may reasonably be construed as falling within the ambit and scope of the appended claims.

Having described our invention what we claim as new and desire to secure by Letters Patent is l. A blade for propellers having a medial portion the edges whereof are parallel and opposed ends converging therefrom in hyperbolic curves to the tips, said blade being uniformly concavo-convex in cross-,section throughout its length and having the tips twisted into a line directly central thereof.

2. A blade for propellers made from a blank of sheet material and having a medial portion the edges whereof are parallel and opposed ends converging from said medial portion in hyperbolic curves, said blade being uniformly concavoeconvex in cross-section throughout its length and having the tips twisted into a line directly central thereof.

3. A propeller blade comprising a single member of a uniformly concavo-conveX cross section throughout its length and having diagonally opposed edges relatively parallel and other diagonally opposed edges formed in hyperbolic curves.

4. A propeller blade comprising a single member of a uniformly concavoronvex cross section throughout its length and Vhaving diagonally opposed edges relativelyv parallel and other diagonally opposed edges formed in hyperbolic curves and constituting continuations of the first mentioned edges.

5. A propeller blade comprising a member having diagonally opposed parallel edges and diagonally opposed hyperbolically formed edges.

6. A propellerblade comprising a member formed to provide opposed blade surfaces of uniform concave convex cross section throughout their length.

7. As a new article of manufacture a propeller blade comprising a single piece of material formed with opposed parallel and curved edges with the curved edges consti-VY tuting continuations .of the parallel edges, the piece of material being spirally twisted at its medial portion to have the extremities thereof lie inthe longitudinal plane of the piece of material.

v8. As a new article of manufacture a propeller blade comprising a single piecerof material formed with opposed parallel and curved edges withthe curved edges constituting continuations of the parallel edges, the piece of material being spirally'twisted at its 'medial portion to have the extremities thereof lie in the longitudinal plane of the piece of material and curved toward'each other with the said piece of material throughout its length having a uniform cross sectional curved surface. Y

ln testimony whereof we, affix our signatures.

- WALTER V. KAMP. THGMAS R.v MACMSECHEN. 

